Peter Fonagy is Freud Memorial Professor of Psychoanalysis and Director of the Sub-Department of Clinical Health Psychology at University College London. He is Chief Executive of the Anna Freud Centre, London. He is a clinical psychologist and a training and supervising analyst in the British Psychoanalytical Society in child and adult analysis. He has published over 200 chapters and articles and has authored or edited several books. Horst Kachele is the former director of the University Clinic for Psychosomatic Medicine and Psychotherapy at Ulm University, Germany (1990 - 2000), also former director of the Research Centre for Psychotherapy, Stuttgart (1988 - 2004); he teaches now at the International Psychoanalytic University in Berlin. Marianne Leuzinger-Bohleber is Professor of Psychoanalytical Psychology at the University of Kassel, Germany, and Director of the Sigmund-Freud Institut, Frankfurt am Main. She is a training analyst of the Germany Psychoanalytical Association and a member of the Swiss Psychoanalytical Society. David Taylor is a training and supervising analyst of the British Psychoanalytical Society. He is chair of the International Psychoanalytical Association's Clinical Research Sub-Committee.